低密度、块状氧化铝气凝胶制备  

Preparation of Low Density,Monolithic Alumina Aerogels

作　　者：高庆福[1] 张长瑞[1] 冯坚[1] 武纬[1] 冯军宗[1] 姜勇刚[1] 

机构地区：[1]CFC国防科技重点实验室国防科技大学航天与材料工程学院,长沙410073

出　　处：《无机化学学报》2008年第9期1456-1460,共5页Chinese Journal of Inorganic Chemistry

基　　金：国防科技重点实验室基金(No9140C8203050604)资助项目

摘　　要：研究了工艺参数对氧化铝溶胶及气凝胶的影响。结果表明,稳定的氧化铝溶胶优化制备工艺为:仲丁醇铝为前驱体,水解温度60℃,仲丁醇铝、乙醇、水的物质的量之比为1∶(8～16)∶1.2;螯合剂乙酰乙酸乙酯能有效控制仲丁醇铝水解缩聚速率,提高溶胶的稳定性;块状氧化铝气凝胶主要成份为多晶勃姆石相,比表面积为447m2.g-1,其强度和密度随乙醇量的增加而降低,密度最低为0.040g.cm-3。氧化铝气凝胶微观结构由许多片叶状颗粒堆积形成,经1200℃热处理后仍保持原有的微观形貌,比表面积为73m2.g-1。The effect of synthesis conditions on alumina sols and aerogels was investigated. The results show that a clear alumina sol is obtained by mixing aluminum tri-sec-butoxide（ASB）, ethanol and water in a molar ratio of 1：8-16：1.2 and stirring at 60 ℃. The chelating reagent ethyl acetoaeetate（Etac）, which controls the hydrolysis and condensation of ASB, improves the stability of alumina sol. The monolithic alumina aerogel with well strength is composed of poly-crystallized boehmite, and the specific surface area is 447 m^2·g^-1. The strength and density of aerogels decrease with the increase of ethanol solvent, and the lowest density is 0.040 g·cm^-3. The microstructure of alumina aerogel consists of randomly connected leaf-like particles. During calcination at 1 200 ℃, the aerogel still keeps the same porous textures and the surface area is 73 m^2·g^-1.

关 键 词：氧化铝气凝胶 螯合剂 勃姆石 比表面积 

分 类 号：O614.31[理学—无机化学]